Human tubular bones are bone formations of an elongated cylindrical shape, less often trihedral. There is no strictly defined configuration. As a rule, the length of such a bone repeatedly prevails over the width. However, the proportions can be very different. The formation and growth of tubular bone is accompanied by several factors, the main of which is the presence of calcium as a chemical element involved in the construction of bone tissue.
The process of formation of cellular structures is quite long. A lack of calcium often leads to curvature of the bones. An excess of this important element can also negatively affect the formation of the skeleton in childhood. In order to prevent bone deformation in a growing organism in time, it is necessary to maintain a balance of chemical elements involved in the process.
Long and short tubular bones
The human skeleton is a logical construct endowed with a number of functional programs. Each part of the body performs its task, and the vital activity of the whole organism depends on the overall coherence of individual sections. Tubularhuman bones are the most important part of the skeleton, they are responsible for the musculoskeletal function. At the same time, the activity of the organism is possible only if all participants in the process interact. Some functions of the bone complexes are programmed to move in a constant mode, such as walking or running. The cyclic repetition of the same actions becomes automatic, impulses are no longer generated in the brain and not even in the central nervous system, but in the muscle tissue involved in the process.
Tubular bones are connected to each other through tendons and muscles. The moving parts of the skeleton interact according to the principle of a hinged mechanism. Such devices in the human body are joints, each of which is covered with a special hyaline cartilage that prevents friction. At the point of mutual contact, the surfaces slide along a certain amplitude, their movement is rational and occurs in a strictly limited mode. The body of the tubular bone is vulnerable, any deviation from the given motion vector causes tension and pain. In the event of extreme disruption of the normal movement pattern, the joint may lose its natural engagement, and thus dislocation occurs.
The long tubular bones of the human skeleton are among the main supporting structures, quite strong and reliable. Nevertheless, they should be protected, not overloaded and often given rest. Long tubular bones are divided into separate types:
- bigtibia;
- tibialis minor;
- femoral;
- beam;
- shoulder;
- elbow.
Short tubular bones:
- metatarsal;
- metacarpal;
- phalanges of fingers.
Most often, short tubular bones are a continuation of long ones.
What tubular bones are levers, one way or another involved in the movement of the body? These are tibia and femur. Short tubular bones provide leverage functions in a more limited range.
Structure
Tubular bones consist of a central part, the diaphysis, which is an elongated cavity ending at both ends with epiphyses. The diaphysis contains a yellow brain, and the epiphyses have a hard spongy texture and are covered with cartilage layers.
The epiphysis is an expanded end of a tubular bone, rounded, having a certain shape, designed for articulation with an adjacent joint. The combination of two or three parts forms a complete joint, functioning in a specific motor program of the body. The contact fragments of the joints have a counter-type shape, when the surface of one half is convex and the other half is concave.
Periosteum
Outside, tubular bones are covered with periosteum, a connective tissue layer. This is a living organic formation, the purpose of which is protective functions.
Organics
Tubular bone substance consists of organic and inorganic substances. The proportions of their contentfluctuate throughout a person's life. Childhood is a period of dominance of organic substances in the body, which give the bones flexibility. With age, the composition of substances gradually changes, inorganic substances that provide strength take their rightful place. These are predominantly calcium s alts.
Physiological device
- The compact substance consists of many bone plates covering the bone in a continuous dense layer. Hard scales are combined into structural units, the so-called osteons. The formed fragments are cylindrical formations of organic properties, inside which nerves and small blood vessels pass.
- Spongy substance is located under compact layers, differs from them in porous structure. In the process of formation of spongy substance, trabeculae are involved - a kind of bone partitions. Much depends on their strength.
- Bone marrow is the main hematopoietic organ in the human body, which is located inside the tubular bones. It is divided into two types: yellow and red. The first is formed by fat cells and is located in the diaphysis - the main part of the tubular bone. The red bone marrow is located in the porous part of the epiphysis and is a reticular tissue densely permeated with small blood vessels. Through these ducts, newly formed cells enter the mainstream. New blood cells are generated from stem cells living in the bone marrow. The process does not stop for a second. There are also osteoclastsosteoblasts that renew bone structures, destroying obsolete ones.
Height
Tubular bones grow in the process of development of special epiphyseal plates. The cartilaginous layer between the epiphyses and the diaphysis can grow intensively in childhood and grow slowly during adolescence, and then maturity. The process is hormonally regulated and does not stop until its physiological completion.
The most active bone growth occurs during physiological traction. The first period lasts from 5 to 7, the second - from 11 to 15 years. Further, the growth of bone formations continues, but at a slower pace. The final phase of skeletal formation ends by the age of 20.
Fractures
Pathological violation of the integrity of individual structures of the skeleton as a result of excessive load can be qualified as fractures of tubular bones.
Main causes of fractures:
- mechanical injury;
- various diseases that cause a decrease in bone strength (osteomyelitis, osteoporosis).
Types of fractures:
- metaphysical;
- epiphyseal;
- diaphyseal.
Signs of a fracture:
- pain that increases sharply with exertion;
- swelling that occurs after some time at the site of injury;
- extensive hematoma that appears 90 minutes after injury;
- Failure of the injured limb.
Signs of an absolute character:
- unnatural limb position;
- chaotic mobility of individual parts;
- characteristic crunch (crepitus) at the site of injury;
- bone breaks in the wound, detected in open fractures.
Recovery
Regeneration and healing of bone tissue occurs due to the formation of new cells at the site of damage. The restoration of the tubular bone can take from several weeks to several months. The healing process requires absolute rest.
The cambial layer of the periosteum and stem cells of the yellow brain are involved in regeneration.
The healing process is divided into four stages:
- Autolysis - the active concentration of leukocytes at the fracture site and the dissolution of dead tissue fragments.
- Proliferation is the reproduction of bone cells as a response to damage with the simultaneous production of cartilage, which then mineralizes.
- Restoration of blood supply disturbed as a result of injury, formation of a compact substance.
- Complete restoration of the bone marrow canal, return of functional abilities.
Diagnosis of fractures should be carried out in a hospital setting. To identify the full picture of the damage, an x-ray examination is necessary to determine the absolute and relative signs of a fracture. After the diagnosis, a course of treatment is carried out, which consists of manipulations to apply a fixing plaster splint. If necessarytraction methods are used. This is followed by long-term monitoring of the patient's condition and drug treatment.
Diagnosis
